Foamy hydraulic fluid

[jhmeg2]

I blew a line on my 642b. Replaced the line and refilled fluid. Lifted and lowered the arms tipped the bucket, and topped off fluid. But the rams seem rough like they aren't getting fluid and the fluid is foamy. How do I bleed out the air from tje system?

 

[Wayne440]

Run it some more maybe. It will take more than a few minutes.

 

[jhmeg2]

Just let it run, or raise and lower the arms? Each time I do it gets frothy. I just dont wanna run the rams dry and or ruin any seals.

 

[foton]

the foam will lube some, make sure it is full , run it and let it sit overnight the bubbles will work out and see what the level is add if necessary and run it again at this point it should be good I would think.

 

[jhmeg2]

Everytime I let it sit the foam dissipates, then I run it and it foams back up.

 

[brdgbldr]

It will eventually stop foaming. Just make sure you keep checking it before you start it. The fluid in the cylinders does not flow through them. It pushes on either side of the piston. So depending on which side of the piston the cylinder has air in it, and how much air, it can take several cycles to get it all out. I've rebuilt and replaced several cylinders and never filled them with oil beforehand.
I usually just move the arms up and down a small amount at first and then check the fluid, let the foam dissipate, repeat until no foam, then move the arms a little further and so on until the foam stops.
The foam in the tank floats to the top so you are not recirculating it. The cylinder will have some fluid in it on both sides of the piston so the seals will be lubricated. The arms being rough could be the fact that only one cylinder is moving them and the other has air in it.
I would be more worried if your arms were acting up and there was no foam.

 

[jhmeg2]

It will eventually stop foaming. Just make sure you keep checking it before you start it. The fluid in the cylinders does not flow through them. It pushes on either side of the piston. So depending on which side of the piston the cylinder has air in it, and how much air, it can take several cycles to get it all out. I've rebuilt and replaced several cylinders and never filled them with oil beforehand.
I usually just move the arms up and down a small amount at first and then check the fluid, let the foam dissipate, repeat until no foam, then move the arms a little further and so on until the foam stops.
The foam in the tank floats to the top so you are not recirculating it. The cylinder will have some fluid in it on both sides of the piston so the seals will be lubricated. The arms being rough could be the fact that only one cylinder is moving them and the other has air in it.
I would be more worried if your arms were acting up and there was no foam.

Great to hear, thanks. I'll keep wotking yhem a little at a time. Cheers.

 

[mrbb]

just saying this too, if there is any water in this fluid, that too can cause it to foam up after it runs a bit, gets warm and mixes well!
but I am guessing that since you drained and refilled, this shouldn;t be your issue!

 

[jhmeg2]

I did not drain and refill it. I blew a line replaced the line and filled the fluid level back u0.

 

[mrbb]

I did not drain and refill it. I blew a line replaced the line and filled the fluid level back u0.

OK well if you wanted too, you could drain some of the foamy fluid into a clear container, let it settle in the sun and see if any water is in it?
but again, NOT saying this is your problem, just something that can cause foamy oils

 

[jhmeg2]

I ran the machine using it and checked the fluid (through the eye) and the foam dissipated and the operation got better. I think it may have worked itself out. Thanks for the help guys.